I think this VCF is malformatted:
gene=TTN;lofteelof=LC;SIFT_score=.;.;.;.;.;sift_pred=.;.;.;.;.;
^
An entire INFO field key can’t be .. Something like FOO=. is fine (though preferred to leave FOO out if the value is missing).
Is it possible that this VCF came from a tool that used semicolon as a delimiter within SIFT_score? That may be the culprit.